20 AET. II. — A. IZUKA : 



Body short and broad, regularly elliptical in outline, measuring 

 37 mm. in length, 15 mm. in breadth, and 6 mm. in height. It 

 consists of 26 segments. 



Prostomium approximately quadrate, its anterior and lateral 

 margins slightly convex, the posterior concave. Eyes of anterior 

 pair about twice as large as those of posterior pair. Median tenta- 

 cular ceratophore about § as long as prostomium ; style 4 times 

 the length of prostomium, Avith subterminal bulb followed by a 

 terminal ülament of about equal tengtli. Lateral tentacles similar 

 in form to the median, but only about § as long ; the ceratophore 

 only .J as long as that of the median tentacle. Tentacular cirri 

 similar in form, the dorsal equalling the median tentacle in length, 

 the ventral somewhat shorter. Subtentacles about as long as the 

 median tentacle, rather stout, densely ciliated. 



Nephridial papillae from the 4th to the 26th segment inclusive. 



Prominent dorsal papillae occur on all segments from tlie 

 2nd to the 20th inclusive, being median on the 2nd and on 15th 

 to 20tli segments, but in double submedian series on Srd to 14tli 

 segments inclusive. Branchial filaments occur on every segment 

 from 3rd to 24th inclusive, except on the 23rd, the last elytra 

 l3earing segment. On elytra-bearing segments the branchial fila- 

 ments arc disposed as follows : One arises from the antero- external 

 and another one from the postero- external margin of elytrophore. 

 The former is unbranched ; the latter is longer, and on 

 typical somites divides into a short medial and a long 

 lateral Ijranch. On each parapodium there are 2 dorsal, 5 or 

 6 anterior, and 4 or 5 posterior filaments, the most external 

 one in each case being bifid. Essentially the same arrangement 

 obtains on cirri-bearing somites, but the filaments arc here more 

 numerous, longer and sometimes even trilid. There arc usually 5 



